The present invention relates to an operating lever device for an offset press in which a series of processes from a plate loading process through a printing process to a blanket cylinder cleaning process are carried out with one operating lever.
Referring to FIG. 1, an offset press 3 includes a plate cylinder, a rubber blanket cylinder 4, and a impression cylinder 5. After an original plate 188 has been loaded onto the plate cylinder 3 by operation of a plate loading device 1, the surface of the plate 188 is coated with moisture supplying solution and ink by a solution supplying device 17 and an inking device 17a. The image of the original plate 188 is transferred onto the rubber blanket cylinder 4 and then printed on a printing sheet which is fed between the rubber cylinder 4 and the compression cylinder 5 by a sheet feeding device 15. After the printing operation, the original plate 188 is unloaded from the plate cylinder 3 and then the rubber blanket cylinder 4 is cleaned by a blanket cylinder cleaning device 2.
Recently, an offset press has been developed in which, after a plate has been loaded on the plate cylinder 3, the remaining processes are automatically carried under the control of a logic circuit. In that offset press, the degree of inking is set before the plate 188 is loaded onto the plate cylinder 3. The degree of inking corresponds to the number of revolutions of the plate cylinder 3 during the time interval which elapses from the instant that form rollers 6 and 7 contact the surface of the plate until the plate contacts the rubber blanket cylinder. The degree of inking further corresponds to the number of revolutions of the plate cylinder during the time interval which elapses from the instant that the plate contacts the rubber blanket cylinder 4 (hereinafter referred to merely as "a rubber cylinder 4", when applicable) until a printing sheet is fed. However, in view of the conditions of the printing machine as well as the skill of the operator, frequently the number of cycles set is too many or too few. Furthermore, sometimes a so-called "insertion error" wherein an original plate 188 is not loaded in place on the plate cylinder 3 may occur. In addition, if a creased original plate 188 is used or an original plate 188 is creased during a plate loading process, the next process is carried out with the creased original plate. Accordingly, the resultant print is undoubtedly unsatisfactory. In this case, it is necessary to remove the plate and to clean the rubber cylinder 4. This removal and cleaning operation is troublesome, wasting time and labor. Thus, the conventional offset press involves a variety of problems yet to be solved.